Mixing and kneading machine



Jan. 29, 1935. c. F. BERAN ET AL MIXING AND KNEADING MACHINE 5Sheets-Sheet l I Filed April 25, 1931 45 54 47 INVE T 3 cumuasFNBCEDEH5N amma scmvsmsra 7/ 0/ TTORN EY5 Jan. 29, 1935. c F, BERAN ETAL 1,989,126

MIXING AND KNEADING MACHINE Filed April 25, 1931 5 Sheets-Sheet 2 AMann)! 3'3? [6 L LL Z5 39 .3 39 38 37 INVENTORS CHARLES F- BERHN acmescmswea Jan. 29, 1935.

c. F. BERANJET A]. 1,989,126

MIXING AND KNEADING MACHINE Filed April 25, 1931 3 Sheets-Sheet 3 JimPatented Jan. 29, 1935 PATENT. optics MIXING AND KNEADING MACHINECharles F. Ber-an, Tuckahoe, N. Y., and George Schneider, Montclair, N.J., assignors'to- Cel anese Corporation of America,

. Delaware a corporation of Application April 25, 1931, SerialNo.;532.7s1, 1 Claim. .(o1..259-1o4 Our present inventionrelates tomixing and kneading machines and more particularly to an apparatus forcarrying out acetylizing and other chemical reactions in the manufactureof cellulose acetate- I v In device s of this type, as heretoforecommonly constructed, the stirrer arms, or agitators, were formedintegral with the shafts attached to the driving means adapted to rotatesaid stirrer arms. This consruction necessitated a complete dismantlingof the machine where a stirrer arm had to bereplacedfor any reason, forexample because of a worn shaft, such wear being caused by the pressureof the gland packing used on said shafts to prevent the escapeof'material or fumes.

Another factor which contributed to lower considerably the efficiency ofthese acetylizers was the ease, relatively speaking, with which thecooling. medium penetrated into the inner shell of the trough throughthejoints, or seams, then, thus spoiling the charge. Whenever a leak wasdiscovered, it was necessaryto take the machine out of, commission,dismantle practically the whole for the purpose of replacing thejointingmaterial which consisted of asbestos or other suitable plasticand acid -resisting compound. This dismantlinginclude'd theremoving ofthe stirring apparatus which was cumbersome because it was formedintegral with the shafts. This was a decidedly costly procedure and itentailed considerable loss of time and labor, the machine remaining idlefor two days and often for a longer period of time during thereconditioning thereof.

It is an object of this invention to provide an improved acetylizerwhich will be free from the above mentioned and other disadvantages andwhich will be especially simple and inexpensive in construction andeflicient in operation.

In one aspect the invention comprises the provision in an acetylizer ofa stirrer arm formed of a plurality of parts. The employment of astirrer arm of this type permits of the use of. different materials forthe various parts. For the portion of the arm contained within thetrough and which comes into contact with the charge, a material may beadopted which is most suitable to withstand the action of the acid usedand which is highly resistive to the abrasive action incident to themixing action. The shafts are desirably formed from a material which isrelatively inexpensive and which is most efiicient in withstanding thefriction of the gland packings.

In another aspect the invention comprises an acetylizer having-a troughthe inner shell of which is formed without a joint or scam, theconstruction and arrangement being such that seepage of the cooling orheating medium into the charge through faulty joints is eliminated. Tothis end the trough may comprise a bronze casting forming an integralstructure of an inner shell and, if desired, a jacket. Alternately, theinner shell may be made from sheet metal forming a single piecepanwithout joints. A jacket may be suitably secured to the pan. 7 Otherobjects and advantages, together with certain details of constructionand combinations of parts,willbe described in the specification andpointed out in the appended claim.

. In the accompanying drawings:

Figure 1 is a front elevational View of the machine embodying ourinvention; 7

Figure 2 is a side elevation of the same, showing in dot-dash lines thetrough in tilted position for emptying and cleaning purposes; Figure 3is a view, partly in section, taken on line 33 in Figure 2 showing theconstruction of the improved trough and stirrer arms;

Figure 4 is an end view, partly in section, show ing the construction ofthetrough. Figures 5 and 6 are side and end, views, respectively, of amodifiediform of trough. I 'Like characters ofr'ef erence" indicatecorresponding parts throughout the several views of the drawings. I

Referring to the drawings, the reference numeral '7 indicates a base inwhich is suitably journaled a shaft 8. A trough 9 is pivotally mountedon the shaft and is adapted for tilting movement relative to the base 7forthe purpose of emptying andcleaning the same.

Referring to Figures 3 and 4, the trough is shown as a casting,preferably of bronze although any suitable acid resisting metal or alloymay be used, comprising an inner shell 11 and an integral jacket 12through which a suitable cooling fluid is circulated by means of pipes13. The inner shell is formed without the joints, or seams, heretoforepresent in troughs of this type thereby eliminating the possibility ofdamage to the charge by cooling fluid coming into contact with thecharge through leaky joints.

In bearing boxes 14 suitably secured to end walls 15 of the trough arejournaled shafts 16, 17, 18 and 19, which extend into the inner shell 11through apertures 21 formed in said end walls. The stirrer arms 22 and23 have integral collars, or hubs, 24 which are keyed to said shafts andare retained thereon by means of nuts 25. Caps 26 secured to hubs 24 byscrews 27 and stufiing boxes 28 fixed to the trough by means of bolts 29are provided for each shaft to prevent leakage of material or fumes.Extending longitudinally along the bottom of the inner shell 11substantially centrally thereof and secured thereto by screw bolts 31 isa saddle 32 which cooperates with the stirrer arms 22 and 23 during amixing operation, as is well understood in the art. By the constructionoutlined above it will be readily observed that we have provided astirrer arm assembly wherein the shafts which normally wear down firstmay be replaced with loss of very little time and without the necessityof removing-the stirrer arms from the trough. All that is required is toloosen and withdraw the shaftand to insert a new one. Q

The trough is provided with a cover 33 in which there is a large opening34 for the purpose offacilitating the cleaning of the trough. A lid 35;adopted to be suitably clamped down while .a;

charge isbeing worked, is fitted to said opening. There is also provideda smaller opening 36, nornyue'see, and through which any material canb'e cliargedinto or discharged from the trough. For the purpose offlushing out the rust and other accumulations which frequently form inthe jack et' of the trough, apertures 37 are formed in the bottonrithereof, said apertures being normally closed by covers 38 suitablyattached by screws 39.

Referring to Figures and 6, there is disclosed a-modified form of troughwhich differentiates from the type of trough shown in Figures 3 and 4 bybeing constructed in two main parts which are made of rolled sheet metalrather than as a singlebasting. The modification provides for a singlepiece inner shell ll'with the complete absence of joints, said shellhaving a plurality of suitable brackets 42 welded or otherwise securedto the outer surface thereof. When required. a a jacket 43 may beattached to the brackets by means of; bolts 44' and nuts 45, theconstruction being such the trough structure is able to withstandconsiderable pressured The stirrer arms are driven 'by'a' suitable geararrangement; generally indicated by reference numeral 46, which isadapted to rotate the arms at different speeds, forward and reverse, asis well understood in the art.

The trough is tilted by a driving arrangement (not shown) which by meansof a chain 4''! rotates a gear 48 fixed on a shaft 49 journaled inbearings 51 formed in the upper extremities of upright members 52attached to base 7- by cross-bars 53. The shaft 49 rotates the gears 54and 55 suitably secured thereto which drive chains 56 and 57,respectively. One end of each of these chains is secured to a bracket,58 attached to the trough by bolts or rivets 59, the other end carryinga counterpoise 61 of suitable weight.

Means are provided to automatically lift the lid 35, hinged to the cover33 at 62, during the tilting movement of thetrough, said meansconsisting of a rod 63 attached at one end to an eye-bolt 64 in the lid35, the other end being mounted for pivotal movement on the shaft 49 bymeans of a loop member 65. It will be readily understood that as thetrough is tilted the lid will be raised and held inopen position bymeans of the above arrangement.

' For the purpose of discharging the contents from units of largecapacity, the trough may be provided at its lowest point with adischarge valve. In such an arrangement, a tilting means is, of course,unnecessary and accordingly the laborand time required for tilting thetrough is saved.

Having thus described our invention whatwe claim as new and desire tosecure by Letters Patent of the United States is:

In an acetylizer, the combination with a onepiece trough having shaftsextending therein, of astirrer arm having integral hubs detachablysecured to said shafts, means carried by said hubs for preventingleakage of material from said trough, a cover for said trough, saidcover having an opening therein, a lid normally closing said opening,means including a shaft for tilting said trough and means for raisingsaid lid during a. tilting movement of said trough comprising a rodsecured to said lid and to said shaft.

CHARLES F. BERAN.

GEORGE SCHNEIDER.

